Biotin (Vitamin B8)

Biotin is the most stable of B vitamins. It is commonly found in two forms: the free vitamin and the protein-bound coenzyme form called biocytin. Biotin is absorbed in the small intestine, and it requires digestion by enzyme biotinidase, which is present in the small intestine. Biotin is synthesized by bacteria in the large intestine, but its absorption is questionable. Biotin containing coenzymes participate in key reactions that produce energy from carbohydrate and synthesize fatty acids and protein.

Biotin deficiency was first recognized because of the effects of a protein called avidin, which is found in raw egg white. Avidin binds and inactivates biotin. Therefore, consumption of raw whites is of concern due to the risk of becoming biotin deficient. Cooking the egg white, however, destroys avidin.

Biotin can be made by gut bacteria and absorbed from the large bowel, so that not all biotin needs to be obtained from food. Theoretically, antibiotics that affect gut bacteria could reduce the amount of biotin available.

Infants may be at risk from biotin deficiency, which shows up as a 'seborrhoeic dermatitis' that responds to biotin. Also, some infants have a metabolic disorder requiring extra biotin. There has been some suggestion that 'cot deaths' or the sudden infant death syndrome may be due, in some cases, to an inadequate intake of biotin.

The biotin in human milk averages about 10 micrograms per 1000 kilocalories (4200 kilojoules) and in infant formulae is usually at least 15 micrograms per 1000 kilocalories. However, a higher concentration of biotin may be preferable for infant formulae because nutrients can be more biologically available to the infant from human milk than from infant formulae.

Common food sources	Liver, kidney, egg yolk, milk, whole grains, nuts and seeds, most fresh vegetables, also made by intestinal bacteria.
Major functions	Helps release energy from carbohydrates; aids in fat synthesis.
Recommended daily intake	Infants: 5 - 6 microg Children: 8 - 12 microg Adolescents: 20 - 25 microg Men & Women: 30 microg Pregnant Women: 30 microg Lactating Women: 35 microg
Deficiency symptoms	Uncommon under normal circumstances; Dermatitis, fatigue; loss of appetite, hair loss (alopecia), nausea, vomiting; depression; muscle pains; anemia, neurological disorders, impaired growth.
Overconsumption symptoms	None
Stability in foods	Biotin is sensitive to air and oxygen and also to alkaline conditions.

Vitamin B8 Food Chart

Cereals, Cakes, Biscuits, Desserts	Content(milligram per 100 grams)
Yeast, dried	200
Bran, wheat	14
Bread, brown	3
Crispbread, rye	7
Bread, white	1
Cake, fruit	4
Chapati	2
Cake, sponge	8
Pancake	5
Rice, boiled	1
Pizza, Cheese & Tomato	3
Custard	2
Custard tart	4
Jam tart	1
Milk pudding	0.1
Porridge	2
Triffle	3

Egg And Chesse Dishes	Content(milligram per 100 grams)
Egg,boiled	25
Egg,fried	25
Omelette	22
Poached	25
Raw	25
Scrambled	20
Macaroni cheese	1
Cauliflower cheese	2
Cheese soufflé	10

Fish and Seafoods	Content(milligram per 100grams)
Roe, Cod, fried	15
Salmon, canned	5
Sardine, canned	4
Tuna, canned in oil	3
Oysters, raw	10
Lobster, boiled	5
Cod, baked	3
Cod, poached	3
Cod, steamed	3

Meat and Meat Products	Content(milligram per 100 grams)
Chicken, boiled	4
Chicken livers, fried	170
Ham, canned	1
Beef, canned	2
Beefburger	2
Backon, fried	2
Lamb, brain, boiled	3
Lamb, heart, roast	8
Lamb, kidney, fried	42
Lamb, Liver, fried	41
Pork, chop	2
Pork, Leg roast	2
Sausage, liver	7
Salami slices	3
Pork, fried/grilled	3

Milk and Milk Products	Content(milligram per 100 grams)
Milk, cow's,cond,skim,sweet	4
Dried,skimmed	16
Dried,whole	10
Goat's	2
Human	0.7
Ice-cream	0.2
Cheese, Camembert	5
Cheddar	2
Parmesan	2

Vegetables	Content(milligram per 100 grams)
Broccoli	0.3
Cauliflower, raw	2
Cauliflower, boiled	1
Cabbage, raw	0.1
Carrots, raw	0.6
Carrots, boiled	0.4
Beans, French, boiled	1
Asparagus, boiled	0.2
Celery Raw	0.1
Cucumber slices	0.4
Lettuce raw, leaves	0.7
Onions, raw	0.9
Onions, boiled	0.6
Parsley, spring	0.4
Peas, canned	0.4
Pumpkin	0.04
Radish	0.4
Spinach leaves	0.1

Fruits	Content(milligram per 100 grams)
Apple	0.2
Avocado pear	3
Blackberries	0.4
Cherries	0.3
Currants, black	2
Grapes	0.2
Grapefruit	0.5
Lemon slices	0.5
Juice	0.3
Orange	0.8
Peach	0.2
Pear	0.1
Plums	0.1
Raspberries	2

Nuts	Content(milligram per 100 grams)
Almond	0.4
Chestnuts	1
Walnut	2

Sauces and condiments	Content(milligram per 100 grams)
Chutney, tomato	1
Mayonnaise	12
Tomato sauce	2

Beverages	Content(milligram per 100 grams)
Beer	0.5

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Vitamins

Vitamins are organic compounds that the body needs for the maintenance of good health and for growth. By convention, the name vitamin is reserved for certain nutrients that the body cannot manufacture and therefore must get from food.

Vitamins contain no useful energy for the body but they do link and regulate the sequence of metabolic reactions that release energy within the food we consume. Vitamins cannot be made in the body and must be obtained in our diet. A well balanced diet provides an adequate quantity of all vitamins regardless of age and level of physical activity.

The two types of vitamins are classified by the materials in which they will dissolve. Fat-soluble vitamins -- vitamins A, D, E and K -- dissolve in fat before they are absorbed in the blood stream to carry out their functions. Excesses of these vitamins are stored in the liver. Because they are stored, they are not needed every day in the diet.

By contrast, water-soluble vitamins dissolve in water and are not stored; they are eliminated in urine. We need a continuous supply of them in our diets. The water-soluble vitamins are the B-complex group and vitamin C. In contrast to the fat-soluble vitamins, the water-soluble vitamins are not easily stored by the body. They are often lost from foods during cooking or are eliminated from the body.

Fat soluble vitamins should not be consumed in excess as they are stored in the body and an excess can result in side effects. An excess of vitamin A may result in irritability, weight loss, dry itchy skin in children and nausea, headache, diarrhea in adults.

An excess of water soluble vitamins should not result in any side effects as they will disperse in the body fluids and voided in the urine.

Water Soluble Vitamins

B-complex vitamins and vitamin C are water-soluble vitamins that are not stored in the body and must be replaced each day. There are eight of them, namely; B1 (thiamine), B2 (riboflavin), B6 (pyridoxine), niacin (nicotinic acid), B12, folic acid, pantothenic acid, and biotin. The water-soluble vitamins, inactive in their so-called free states, must be activated to their coenzyme forms.

The water-soluble vitamins are absorbed in our intestine, pass directly to the blood, and are carried to the tissues in which they will be utilized. Vitamin B12 requires a substance known as “intrinsic factor for absorption".

Water-soluble vitamins usually are excreted in the urine on a daily basis. Thiamine (B1), riboflavin (B2), pyridoxine (B6), ascorbic acid (C), pantothenic acid, and biotin appear in urine as free vitamins Tissue storage capacity of water soluble vitamins is limited and, as the tissues become saturated, the rate of excretion increases sharply. This keeps us from overdosing but this is also why we need to take these vitamins daily. Unlike the other water-soluble vitamins, however, vitamin B12 is excreted solely in the feces. Some folic acid and biotin is also normally excreted in this way. Although fecal excretion of water-soluble vitamins (other than vitamin B12, folic acid, and biotin) occurs, their source probably is the intestinal bacteria, which synthesize the vitamins, rather than vitamins that we have eaten and used.

The effects of the water-soluble vitamins are obvious in many parts of the body. They act as coenzymes to help the body obtain energy from food. They also are important for normal appetite, good vision, healthy skin, healthy nervous system and red blood cell formation.
We need a continuous supply of them in our diets to ensure proper health and nutrition.

Fat Soluble Vitamins

Fat-soluble vitamins are absorbed, together with fat from the intestine, into the circulation. Once absorbed into the circulation these vitamins are carried to the liver where they are stored.
Vitamins A, D, E and K make up the fat soluble vitamins. Vitamins A, D and K are stored in the liver and vitamin E is distributed throughout the body's fatty tissues.

This storage capability makes the fat-soluble vitamins potentially toxins. Care should be exercised when taking the fat-soluble vitamins. The fat-soluble vitamins, especially vitamin A, should be consumed with care because of their storage capabilities. They have the potential of building up to harmful levels.

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Nutrition and Calorie

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For every physical activity, the body requires energy and the amount depends on the duration and type of activity. Energy is measured in kcal and is obtained from the body stores or the food we eat.

Carefully planned nutrition must provide an energy balance and a nutrient balance.

The nutrients are:

Proteins - essential to growth and repair of muscle and other body tissues
Fats - one source of energy and important in relation to fat soluble vitamins
Carbohydrates - our main source of energy
Minerals - those inorganic elements occurring in the body and which are critical to its normal functions
Vitamins - water and fat soluble vitamins play important roles in many chemical processes in the body
Water - essential to normal body function - as a vehicle for carrying other nutrients and because 60% of the human body is water
Roughage - the fibrous indigestible portion of our diet essential to health of the digestive system


What are the daily energy requirements?

Personal energy requirement = basic energy requirements + extra energy requirements
Basic energy requirements (BER)
For every Kg of body weight 1.3 kcal is required every hour. (An athlete weighing 50Kg would require 1.3 × 24hrs × 50Kg = 1560 kcal/day)


Extra energy requirements (EER)

For each hours training you require an additional 8.5 kcal for each Kg of body weight. (For a two hour training session our 50Kg athlete would require 8.5 × 2hrs × 50Kg = 850 kcal)
An athlete weighing 50Kg who trains for two hours would require an intake of approx. 2410 kcal (BER + EER = 1560 + 850)



Energy Fuel

Like fuel for a car, the energy we need has to be blended. The blend that we require is as follows:
57% Carbohydrates (sugar, sweets, bread, cakes)
30% Fats (dairy products, oil)
13% Protein (eggs, milk, meat, poultry, fish)
The energy yield per gram is as follows: Carbohydrate - 4 kcal, Fats - 9 kcal and Protein - 4 kcal. (Note: 1 calorie = 1 Kcal)
What does a 50 kg athlete require in terms of carbohydrates, fats and protein?
Carbohydrates - 57% of 2410 = 1374 kcal - at 4 kcal per gram = 1374 ÷ 4=343 grams
Fats - 30% of 2410 = 723 kcal - at 9 kcal per gram = 723 ÷ 9 = 80 grams
Protein - 13% of 2410 = 313 kcal - at 4 kcal per gram = 313 ÷ 4=78 grams
Our 50kg athlete requires 343 grams of Carbohydrates, 80 grams of Fat and 78 grams of Protein.


Calories Versus Nutrition

Calories are strictly neutral i.e. from an energy viewpoint it doesn't matter whether you eat a healthy 500 calorie meal (eg. meat, potatoes and vegetables) or two 250-calorie candy bars. Both offer 500 calories worth of energy.
But energy/calories alone will not keep you healthy - the calories you eat must contain sufficient nutrition to maintain your organs and tissue in good health, otherwise your well-being and energy levels will suffer.

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